where proj='lcc' selects the Lambert conformal conic
projection for the x/y points, and ellps='clrk66' selects the
reference ellipsoid for the lat/lng coordinates. The other
coordinates are LCC parameters that select the AWIPS 221
and AWIPS 226 projections respectively (lat_1
corresponds to Latin1, lat_2 corresponds to Latin2, and lon_0
corresponds to Lov; see this description of the
two-standard-parallel LCC and its PROJ.4 parameters).